Negative pressure drainage medical sponge and preparation method thereof

Abstract

The application discloses a kind of negative pressure drainage medical polyurethane sponge and preparation method thereof.Belongs to medical material technical field, using the preparation method provided by the application, a kind of new porous medical polyurethane sponge is prepared, which is wrapped with smooth silicone coating having physiological inertia, biocompatibility and low surface energy characteristics.The new medical porous sponge not only has good liquid conducting performance, comfortable wound experience, but also does not adhere to the new granulation at wound site for a long time, so as to avoid secondary wound trauma during dressing change.Therefore, it has very significant effect on the use of negative pressure drainage technology.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of medical materials, more particularly to a medical sponge for negative pressure drainage and a preparation method thereof. BACKGROUND

[0002] The negative pressure drainage sponge is mainly used for vacuum sealing drainage technology, i.e. VSD technology, which is a revolutionary achievement for promoting wound healing. The technology mainly uses a biological semi-permeable membrane to close an open wound, uses a special negative pressure machine to generate a certain negative pressure, and acts on a cleaned wound through a drainage tube and a porous sponge. The therapy can accelerate blood circulation at a wound site, significantly promote new blood vessels into the wound, stimulate the growth of granulation tissue, fully drain, reduce edema, reduce pollution, inhibit bacterial growth, and can directly accelerate wound healing. It is a high-efficiency, simple and economical pure physical therapy for promoting wound healing.

[0003] However, the sponge material used for the negative pressure drainage technology must have good liquid guiding performance to remove pus and tissue fluid in the wound, and the soft texture is also an important aspect of the negative pressure drainage sponge. In the actual application process of the negative pressure drainage sponge, due to the long replacement cycle, the newly generated granulation is easily adhered and entangled with the filament diameter of the porous polyurethane sponge in the long-term contact with the wound, thereby causing damage to the newly generated granulation in the replacement process of the sponge, and greatly reducing the wound healing time. Therefore, it is of great practical significance to design a sponge material that can meet the performance of negative pressure drainage, has soft texture, and does not cause adhesion with the newly generated granulation of the wound. SUMMARY

[0004] In view of the problems of the traditional porous negative pressure drainage sponge, such as insufficient softness, easy to cause a stinging sensation to the patient in the process of adhering to the wound, and the newly generated granulation is easily adhered and entangled with the filament diameter of the sponge in the long-term direct contact with the wound, thereby causing damage to the newly generated granulation in the replacement process of the sponge and delaying the wound healing speed, and in view of the practical needs of the patients for a porous sponge that can solve the above problems and meet the needs of the negative pressure drainage technology, one object of the present application is to provide a medical sponge for negative pressure drainage.

[0005] According to one embodiment of the present application, a medical sponge for negative pressure drainage is provided, which has a fully open three-dimensional network structure with an average pore size of 1.2-2.1 mm, and has good liquid guiding performance.

[0006] In one embodiment, the medical sponge for negative pressure drainage has a silicone coating layer on the filament diameter of the three-dimensional network structure, with an average thickness of 20-50 um, which can effectively prevent the newly generated granulation of the wound from being adhered and entangled with the filament diameter of the main body (polyurethane component).

[0007] In one embodiment, the negative pressure drainage medical sponge has a very comfortable skin-friendly feeling, a hardness of 30-60 degrees (obtained by LX-F sponge hardness tester test), and does not cause a stinging feeling when directly attached to a wound;

[0008] In one embodiment, the negative pressure drainage medical sponge is non-biotoxic and can be directly contacted with a patient's wound for a long time.

[0009] In one embodiment, the negative pressure drainage medical sponge is composed of a completely open-cell polyurethane net foam with a three-dimensional structure and a silicone coating.

[0010] In one embodiment, the polyurethane net foam used in the negative pressure drainage medical sponge is obtained by removing the cell membrane of a polyurethane sponge through net explosion.

[0011] The negative pressure drainage medical sponge in this scheme has the following advantages:

[0012] 1. The completely open-cell three-dimensional structure has an average pore size of 1.2-2.1 mm, and can exhibit good liquid guiding performance under the action of a special negative pressure machine.

[0013] 2. The very comfortable skin-friendly feeling has a hardness of 30-60 degrees (obtained by LX-F sponge hardness tester test), and does not cause a stinging feeling when directly attached to a wound.

[0014] 3. The three-dimensional network structure with an average silicone coating thickness of 20-50 um can effectively prevent the adhesion and entanglement of the newly formed granulation tissue of the wound and the filament diameter main body (polyurethane component).

[0015] 4. Non-biotoxic, can be directly contacted with a patient's wound for a long time.

[0016] Another object of the present application is to provide a preparation method of a negative pressure drainage medical sponge.

[0017] According to another aspect of the present application, a preparation method of a negative pressure drainage medical sponge is provided, comprising the following steps:

[0018] 1. Preparation of a completely open-cell polyurethane net foam with a three-dimensional structure:

[0019] Select a 30-55 ppi polyester / polyether type polyurethane sponge and net blast it in a net blasting machine to obtain a polyurethane net foam.

[0020] 2. Preparation of a liquid silicone for impregnating the negative pressure drainage medical polyurethane sponge;

[0021] 3. Preparation of a negative pressure drainage medical polyurethane sponge;

[0022] The polyurethane net bubble is completely immersed into the prepared liquid silicone, the excess liquid silicone is squeezed and removed, and high-temperature drying and curing at 150 DEG C are carried out to obtain the negative pressure drainage medical polyurethane sponge with the three-dimensional structure and the organic silicon coating on the wire diameter of the net bubble.

[0023] The viscosity of the liquid silicone for the negative pressure drainage medical polyurethane sponge is 1800 mPa·S / 25 DEG C-6100 mPa·S / 25 DEG C, the curing / operation time at room temperature (25 DEG C) is 7-9 h, the short curing time at 130 DEG C-160 DEG C is 200 s-400 s, and the hardness after curing (liquid silicone curing, non-immersed sponge) is 10-20 Shore A.

[0024] The liquid silicone for the negative pressure drainage immersed sponge has a tear strength of 3-7 KN / m and an elongation at break of 500%-900% after curing, so that the immersed sponge is not affected in normal use due to the fracture and falling of the silicone attached to the wire diameter of the porous sponge caused by friction and bending during the negative pressure drainage operation.

[0025] The liquid silicone for the negative pressure drainage immersed sponge is composed of A and B components, and the A and B components are mixed and stirred uniformly in a certain proportion to obtain the liquid silicone.

[0026] The mixing ratio of the A and B components of the liquid silicone for the negative pressure drainage immersed sponge is one of 5:1-1:1-1:5, preferably one of 3:1-1:1-1:3, more preferably one of 1:1-1:2, and most preferably 1:1.

[0027] The A component of the liquid silicone for the negative pressure drainage immersed sponge comprises base glue, end-vinyl silicone oil and side-chain silane-containing polysiloxane.

[0028] The B component of the liquid silicone for the negative pressure drainage immersed sponge comprises base glue, end-vinyl silicone oil, side-chain silane-containing polysiloxane, catalyst and inhibitor.

[0029] The viscosity of the vinyl silicone oil of the liquid silicone for the negative pressure drainage immersed sponge is 1000 mPa·S / 25 DEG C-8000 mPa·S / 25 DEG C, the content of the silane group of the side-chain silane-containing polysiloxane is 5 mmol / g-16 mmol / g, and the base glue is a commercially available product.

[0030] The liquid silicone catalyst for the negative pressure drainage impregnated sponge is one or more of the eighth group metal, inorganic compound, organic complex; preferably, the catalyst is one or more of the elemental metal platinum, inorganic compound, organic complex; more preferably, the catalyst is the organic complex of the metal platinum; most preferably, the catalyst is platinum(0)-1,3-divinyl-1,1,3,3-tetramethyldisiloxane, i.e., Karstedt's reagent; and the inhibitor is an alkynyl alcohol.

[0031] The preparation method of the liquid silicone for the negative pressure drainage impregnated sponge comprises the following steps:

[0032] 1) Preparation of A component

[0033] The base glue, end-vinyl silicone oil and polysiloxane containing silicon-hydrogen groups in the side chain that are calculated and weighed are stirred and dispersed by a high-speed dispersion machine at a speed of 1000 rpm for 10 min to obtain the A component;

[0034] 2) Preparation of B component

[0035] The base glue, end-vinyl silicone oil and polysiloxane containing silicon-hydrogen groups in the side chain that are calculated and weighed are stirred and dispersed by a high-speed dispersion machine at a speed of 1000 rpm for 10 min, and then the calculated and weighed catalyst and inhibitor are added to the uniformly stirred and dispersed mixture, and stirred and dispersed at a speed of 300 rpm for 2-3 min to obtain the B component.

[0036] 3) Preparation of the liquid silicone for the negative pressure drainage impregnated sponge

[0037] In use, the A component and the B component are weighed according to the proportion, and then stirred and dispersed by a high-speed dispersion machine at a speed of 500 rpm for 2 min to obtain the required liquid silicone for the negative pressure drainage impregnated sponge.

[0038] The liquid silicone for negative pressure drainage and impregnated sponge has a viscosity of 1800 mPa·S / 25℃-6100 mPa·S / 25℃ to adapt to the impregnation operation requirements of sponges with different pore sizes, a lower hardness of 10-20 Shore A to ensure that the impregnated sponge does not cause obvious stinging sensation to the patient's wound when used, an operation time of 7-9 h at room temperature (25℃) to meet the requirement that the liquid silicone in the trough does not solidify before it is used up, a shorter solidification time of 200 s-400 s at 130℃-160℃ to ensure that the liquid silicone attached to the wire diameter of the open-cell sponge is quickly solidified without dripping and detaching from the wire diameter, and a tear strength of 3-7 KN / m and an elongation at break of 500%-900% to ensure that the impregnated sponge does not cause the silicone attached and solidified on the wire diameter of the open-cell sponge to break off due to friction and bending during negative pressure drainage operation, thereby affecting normal use. Based on the above advantages, the liquid silicone for negative pressure drainage and impregnated sponge is very suitable for the preparation of negative pressure drainage and impregnated sponge, and provides high-quality and more convenient negative pressure drainage sponge for VSD technology.

[0039] As for the liquid silicone, the high-viscosity vinyl silicone oil has a longer molecular weight and better flexibility. Under the condition of similar viscosity (the viscosity difference between the high-hydrogen content silicone oil and the low-hydrogen content silicone oil is not more than 100 mPa·S / 25℃), the low-hydrogen content silicone oil has fewer reaction points (lower crosslinking degree), so the amount used is more under the same conditions (the type and amount of vinyl silicone oil are fixed), and the high-hydrogen content silicone oil has more reaction points (higher crosslinking degree), so the amount used is less under the same conditions (under the condition that the type and amount of vinyl silicone oil are fixed, the amount of high-hydrogen content silicone oil consumed is 3 times that of low-hydrogen content silicone oil with a hydrogen content of 5 mmol / g). Therefore, the high-viscosity vinyl silicone oil is compounded with low-viscosity vinyl silicone oil in a specific ratio, and is supplemented with a high-hydrogen content silicone oil with a suitable hydrogen content, so as to ensure that the viscosity of the obtained liquid silicone is low, the hardness of the obtained silicone is low, and the elongation is high, thereby solving the problems of high hardness and low elongation caused by the use of low-viscosity vinyl silicone oil alone, and the problem of poor impregnation of negative pressure drainage porous sponge during impregnation operation caused by the use of high-viscosity vinyl silicone oil alone.

[0040] According to the application, a negative pressure drainage medical polyurethane sponge is provided, which is composed of a fully open-cell polyurethane foam with a three-dimensional structure and a silicone coating on the foam filament diameter; the average pore size of the foam is 1.2-2.1 mm, the thickness of the silicone coating is 20-50 um, the hardness is 30-60 degrees (obtained by testing with a LX-F sponge hardness tester), has no biological toxicity, good liquid conductivity, comfortable skin feeling, can be directly attached to the wound for a long time without causing a stinging sensation, and can effectively prevent the adhesion and entanglement of the newly formed granulation tissue and the filament body (polyurethane component) of the wound, thereby avoiding the damage to the newly formed granulation tissue caused by the sponge replacement process, affecting the wound healing speed and other problems. Based on the above advantages, the use of the negative pressure drainage medical polyurethane sponge has a very significant effect on the improvement of the negative pressure drainage technology. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application will be further described in detail below with examples. It should be understood that the specific examples described herein are only used to explain the present application and not to limit the present application.

[0042] The following are specific examples:

[0043] All the basic raw materials used in the following examples are commercially available.

[0044] Example 1

[0045] The preparation of the negative pressure drainage medical polyurethane sponge includes the following steps:

[0046] 1) Preparation of fully open-cell polyurethane foam with three-dimensional structure;

[0047] Select a 30 ppi polyester / polyether type polyurethane sponge and net blast it in a net blast machine to obtain a polyurethane foam;

[0048] 2) Preparation of liquid silicone for impregnation of the negative pressure drainage medical polyurethane sponge;

[0049] Prepare a liquid silicone with a viscosity of 6080 mPa·S / 25℃;

[0050] 3) Preparation of the negative pressure drainage medical polyurethane sponge;

[0051] Submerge the polyurethane foam in the prepared liquid silicone, squeeze out the excess liquid silicone, and dry and cure at 150℃ to obtain a negative pressure drainage medical polyurethane sponge with a three-dimensional structure of the foam filament coated with a silicone coating.

[0052] Example 2

[0053] The difference between Example 2 and Example 1 is that the 40 ppi reticulated foam is selected in step 1), and the viscosity of the liquid silicone prepared in step 2) is 3650 mPa·S / 25℃;

[0054] Example 3

[0055] The difference between Example 3 and Example 1 is that the 55 ppi reticulated foam is selected in step 1), and the viscosity of the liquid silicone prepared in step 2) is 1800 mPa·S / 25℃;

[0056] Comparative Example 1

[0057] The 30 ppi polyurethane reticulated foam obtained in step 1) of Example 1 is selected as the negative pressure drainage medical polyurethane sponge;

[0058] Comparative Example 2

[0059] The 40 ppi polyurethane reticulated foam obtained in step 1) of Example 1 is selected as the negative pressure drainage medical polyurethane sponge;

[0060] Comparative Example 3

[0061] The 55 ppi polyurethane reticulated foam obtained in step 1) of Example 1 is selected as the negative pressure drainage medical polyurethane sponge;

[0062] The performance test indexes of the negative pressure drainage medical polyurethane sponge obtained in Examples 1-3 and Comparative Examples 1-3 are shown in Table 1:

[0063]

[0064] As can be seen from the above table, by curing a layer of silicone coating on the filament diameter of the three-dimensional structure of the polyurethane reticulated foam, the hardness of the polyurethane sponge can be significantly reduced, and a more comfortable skin-friendly feeling can be obtained. By adjusting the matching of polyurethane reticulated foams with different cell sizes and liquid silicones with different viscosities, negative pressure drainage medical polyurethane sponges with different hardnesses can be prepared to meet different skin feeling needs. At the same time, by adjusting the thickness of the silicone coating within a suitable range, the problems of new granulation drilling into and adhesion with the polyurethane filament diameter due to too thin coating and the problem of affected sponge liquid guiding performance due to too thick coating can be avoided.

[0065] Preparation of liquid silicone

[0066] Example 1

[0067] The preparation of the liquid silicone for negative pressure drainage impregnated sponge includes the following steps:

[0068] 1) Preparation of component A

[0069] Weigh 5g base glue, 47.5g vinyl silicone oil with viscosity of 1000mPa-s / 25℃, 47.5g vinyl silicone oil with viscosity of 8000mPa-s / 25℃, 1.28g hydrogen-containing silicone oil with hydrogen content of 5mmol / g, 0.20g hydrogen-containing silicone oil with hydrogen content of 16mmol / g, and stir and disperse them in a high-speed disperser at a speed of 1000rpm for 10 minutes to obtain component A.

[0070] 2) Preparation of component B

[0071] Weigh 5g base glue, 47.5g vinyl silicone oil with viscosity of 1000mPa-s / 25℃, 47.5g vinyl silicone oil with viscosity of 8000mPa-s / 25℃, 1.28g hydrogen-containing silicone oil with hydrogen content of 5mmol / g, 0.20g hydrogen-containing silicone oil with hydrogen content of 16mmol / g, and stir and disperse them in a high-speed disperser at a speed of 1000rpm for 10 minutes, then add 0.027g Kastle test reagent and 0.0014g inhibitor to the uniformly dispersed mixture, and stir and disperse them at a speed of 300rpm for 2-3 minutes.

[0072]

[0073] to obtain component B.

[0074] 3) Preparation of liquid silicone rubber for negative pressure drainage and impregnated sponge

[0075] In use, component A and component B are weighed according to the proportion, and then stirred and dispersed in a high-speed disperser at a speed of 500rpm for 2 minutes to obtain the required liquid silicone rubber for negative pressure drainage and impregnated sponge.

[0076] Example Two

[0077] The difference between Example Two and Example One is that in component A and component B, the viscosity of the vinyl silicone oil is 3000mPa-s / 25℃ and 5000mPa-s / 25℃, the hydrogen content of the hydrogen-containing silicone oil is 10mmol / g, and the addition amount is 0.77g respectively; and the amount of the inhibitor in component B is 0.0009g.

[0078] Example Three

[0079] The difference between Example Three and Example One is that in component A and component B, the viscosity of the vinyl silicone oil is 3000mPa-s / 25℃ and 8000mPa-s / 25℃, the hydrogen content of the hydrogen-containing silicone oil is 10mmol / g, and the addition amount is 0.73g respectively; and the amount of the inhibitor in component B is 0.0027g.

[0080] Example Four

[0081] ​The difference between Example 4 and Example 1 is that in Component A and Component B, the viscosity of the vinyl silicone oil is 1000 mPa·S / 25℃ and 3000 mPa·S / 25℃, the hydrogen content of the hydrogen-containing silicone oil is 10 mmol / g, and the amount added is 1.05g respectively.

[0082] Example 5

[0083] The difference between Example 5 and Example 1 is that in Component A and Component B, the viscosity of the vinyl silicone oil is 1000 mPa·S / 25℃ and 5000 mPa·S / 25℃, the hydrogen content of the hydrogen-containing silicone oil is 10 mmol / g, and the amount added is 1.00g respectively.

[0084] Example 6

[0085] The difference between Example 6 and Example 1 is that in Component A and Component B, the viscosity of the vinyl silicone oil is 5000 mPa·S / 25℃ and 8000 mPa·S / 25℃, the hydrogen content of the hydrogen-containing silicone oil is 10 mmol / g, and the amount added is 0.68g respectively.

[0086] Comparative Example 1

[0087] The preparation of liquid silicone for negative pressure drainage impregnated sponge includes the following steps:

[0088] 1) Preparation of Component A

[0089] Weigh 5g of base adhesive, 95g of vinyl silicone oil with a viscosity of 1000mPa·S / 25℃, and 0.80g of hydrogen-containing silicone oil (hydrogen content 16mmol / g) and disperse them in a high-speed disperser at a speed of 1000rpm for 10min to obtain component A.

[0090] 2) Preparation of Component B

[0091] Weigh out 5g of base adhesive, 95g of vinyl silicone oil with a viscosity of 1000mPa·S / 25℃, and 0.80g of...

[0092] Hydrogen-containing silicone oil (hydrogen content 16 mmol / g) was stirred and dispersed at 1000 rpm for 10 min. Then, 0.027 g of Cabot reagent and 0.0014 g of inhibitor were added to the well-dispersed mixture, and the mixture was stirred and dispersed at 300 rpm for 2-3 min to obtain component B.

[0093] 3) Preparation of liquid silicone for negative pressure drainage impregnated sponge

[0094] When using, weigh out components A and B according to the specified ratio and then disperse them using a high-speed disperser at 500 rpm.

[0095] Stirring and dispersing at a certain speed for 2 minutes yields the liquid silicone for the required negative pressure drainage impregnated sponge.

[0096] Comparative Example 2

[0097] The preparation of the liquid silicone for negative pressure drainage and impregnated sponge includes the following steps:

[0098] 1) Preparation of A component

[0099] 5g of base glue, 95g of vinyl silicone oil with a viscosity of 1000 mPa-s / 25℃, and 2.56g of hydrogen-containing silicone oil (hydrogen content of 5mmol / g) were weighed and stirred and dispersed in a high-speed dispersion machine at a speed of 1000 rpm for 10 minutes to obtain A component;

[0100] 2) Preparation of B component

[0101] 5g of base glue, 95g of vinyl silicone oil with a viscosity of 1000 mPa-s / 25℃, and 2.56g of hydrogen-containing silicone oil (hydrogen content of 5mmol / g) were weighed and stirred and dispersed at a speed of 1000 rpm for 10 minutes, and then 0.027g of Carbother reagent,

[0102] 0.0014g of inhibitor was added to the uniformly stirred and dispersed mixture, and stirred and dispersed at a speed of 300 rpm for 2-3 minutes to obtain B component.

[0103] 3) Preparation of liquid silicone for negative pressure drainage and impregnated sponge

[0104] In use, A component and B component were weighed in proportion, stirred and dispersed in a high-speed dispersion machine at a speed of 500 rpm for 2 minutes to obtain the required liquid silicone for negative pressure drainage and impregnated sponge.

[0105] Comparative Example 3

[0106] The preparation of the liquid silicone for negative pressure drainage and impregnated sponge includes the following steps:

[0107] 1) Preparation of A component

[0108] 5g of base glue, 95g of vinyl silicone oil with a viscosity of 8000 mPa-s / 25℃, and 0.4g of hydrogen-containing silicone oil (hydrogen content of 16mmol / g) were weighed and stirred and dispersed in a high-speed dispersion machine at a speed of 1000 rpm for 10 minutes to obtain A component;

[0109] 2) Preparation of B component

[0110] 5g of base glue, 95g of vinyl silicone oil with a viscosity of 8000 mPa-s / 25℃, and 0.4g of hydrogen-containing silicone oil (hydrogen content of 16mmol / g) were weighed and stirred and dispersed at a speed of 1000 rpm for 10 minutes, and then 0.027g of Carbother reagent,

[0111] 0.0014g of the inhibitor, and stirring and dispersing for 2-3 minutes at a rotation speed of 300 rpm to obtain component B.

[0112] 3) Preparation of liquid silicone rubber for negative pressure drainage and impregnated sponge

[0113] In use, component A and component B are weighed according to the proportion, and stirred and dispersed for 2 minutes at a rotation speed of 500 rpm using a high-speed dispersion machine to obtain the required liquid silicone rubber for negative pressure drainage and impregnated sponge.

[0114] In use, component A and component B are weighed according to the proportion, and stirred and dispersed for 2 minutes at a rotation speed of 500 rpm using a high-speed dispersion machine to obtain the required liquid silicone rubber for negative pressure drainage and impregnated sponge.

[0115] The performance test indexes of the liquid silicone rubber for negative pressure drainage and impregnated sponge obtained in each example and comparative example are shown in the following table:

[0116]

[0117]

[0118] Note: The hardness, tear strength and elongation at break of the liquid silicone rubber are tested by a 2mm-thick sheet cured at 150°C / 400s; the operation time of the liquid silicone rubber is the curing time at 25°C; a porous sponge with a thickness of 50mm, an average pore size of 1.2mm (a commonly used pore size of traditional negative pressure drainage porous sponge) is placed in a stainless steel tank, the porous sponge is submerged with the liquid silicone rubber, and after five cycles of repeated squeezing / pressure relief / squeezing, the porous sponge is taken out, the excess liquid silicone rubber is pressed out using a press roller, and then the porous sponge is cured at high temperature in an oven at 150°C; the porous sponge is taken out, and if there is no obvious line at the middle position of the thickness of the porous sponge, the impregnation effect is PASS, otherwise it is FAIL.

[0119] As shown in the above table, the liquid silicone rubber obtained in Examples 1 to 5 has a hardness not more than 20 Shore A, is relatively soft, and has high tear strength and elongation, and is very suitable for the impregnation of negative pressure drainage porous sponge which is directly contacted with a wound. After a layer of the above silicone rubber is solidified on the surface of the traditional negative pressure drainage porous sponge, the hardness of the negative pressure drainage porous sponge can be reduced, and the pain caused to the patient during use can be reduced. Meanwhile, the silicone rubber has good physiological inertia and low surface energy, and after a layer of the above silicone rubber is solidified on the surface of the traditional negative pressure drainage porous sponge, the problems of adhesion of the traditional negative pressure drainage porous sponge to a wound and growth of granulation into the wound during use can be avoided, and the problem of damage of the newly grown granulation during replacement of the negative pressure drainage porous sponge can be avoided, and the speed of wound healing can be greatly improved. As shown in the above table, the liquid silicone rubber obtained in Examples 1 to 5 has moderate viscosity and qualified impregnation effect, and can effectively impregnate the traditional negative pressure drainage porous sponge. The liquid silicone rubber obtained in Example 6 and Comparative Example 3 has lower hardness than that of Examples 1 to 5, but has high viscosity and cannot effectively impregnate the traditional negative pressure drainage porous sponge. The liquid silicone rubber obtained in Comparative Examples 1 and 2 has low viscosity and can effectively impregnate the traditional negative pressure drainage porous sponge, but the solidified silicone rubber has high hardness, can obviously cause pain to the patient, and has low tear strength and elongation, and is not suitable for use as the raw material for impregnation of the negative pressure drainage porous sponge.

[0120] As compared with Comparative Examples 1 to 3 and Examples 1 to 5, by adjusting the viscosity of the vinyl silicone oil in components A and B, especially by compounding the high and low viscosity vinyl silicone oils, and matching the hydrogen-containing silicone oil with a suitable hydrogen content, the viscosity of the obtained liquid silicone rubber can be kept low enough to impregnate the traditional negative pressure drainage porous sponge, and the hardness of the solidified silicone rubber can be kept low, and the tear strength and elongation can be kept high, and the problems of high hardness, low tear strength and elongation caused by the use of low viscosity vinyl silicone oil alone, and the problem of poor impregnation of the negative pressure drainage porous sponge during impregnation caused by the use of high viscosity vinyl silicone oil alone can be effectively solved.

[0121] As shown in Table 1, by adjusting the addition amount and ratio of the catalyst and inhibitor in component B, and the viscosity of the vinyl silicone oil in components A and B (the higher the viscosity, the lower the reactivity, and the longer the reaction / curing time), the operation time at room temperature and the curing time at high temperature of the liquid silicone rubber can be adjusted to adapt to different production operation requirements.

[0122] Those skilled in the art will easily understand that the above description is only the preferred embodiment of the present application, and is not intended to limit the present application, and any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for producing a negative pressure wound therapy medical polyurethane sponge, characterized by, The polyurethane sponge has a fully open three-dimensional network structure with an average pore diameter of 1.2-2.1 mm; a layer of silicone coating is provided on the three-dimensional network structure with an average thickness of 20-50 um, and the silicone coating has good performance of preventing the new granulation of a wound from adhering to the main body of the wire diameter; the preparation method comprises the following steps: 1) Preparation of a fully open three-dimensional structure polyurethane sponge Select a polyester / polyether type polyurethane sponge with a wire diameter of 30-55 ppi, and perform net blasting in a net blasting machine to obtain a polyurethane sponge; 2) Preparation of a liquid silicone for a negative pressure drainage medical polyurethane sponge (1) Preparation of A component The base glue, end-vinyl silicone oil and side-chain silicon-hydrogen-containing polysiloxane are stirred and dispersed at a speed of 1000 rpm for 10 min by using a high-speed dispersion machine to obtain A component; (2) Preparation of B component The base glue, end-vinyl silicone oil and side-chain silicon-hydrogen-containing polysiloxane are stirred and dispersed at a speed of 1000 rpm for 10 min by using a high-speed dispersion machine, and then the catalyst and inhibitor are added into the uniformly mixed mixture, and stirred and dispersed at a speed of 300 rpm for 2-3 min to obtain B component; (3) Preparation of a liquid silicone for a negative pressure drainage medical polyurethane sponge In use, A component and B component are weighed according to the proportion, and then stirred and dispersed at a speed of 500 rpm for 2 min by using a high-speed dispersion machine to obtain the required liquid silicone for a negative pressure drainage medical polyurethane sponge; 3) Preparation of a negative pressure drainage medical polyurethane sponge The polyurethane sponge is fully immersed in the prepared liquid silicone, the excess liquid silicone is removed by extrusion, and the negative pressure drainage medical polyurethane sponge with a three-dimensional network structure and a silicone coating on the wire diameter is obtained by high-temperature drying and curing at 150 DEG C.

2. The method of producing a negative pressure wound therapy medical polyurethane sponge according to claim 1, characterized in that, The hardness of the medical polyurethane sponge is 30-60 degrees.

3. The method of claim 1, wherein the negative pressure wound therapy medical polyurethane sponge is prepared by the steps of: The medical polyurethane sponge has no biological toxicity, and can be directly contacted with a patient's wound for a long time.

4. The method of claim 1, wherein the negative pressure wound therapy medical polyurethane sponge is prepared by the steps of: The silicone coating is obtained by curing the liquid silicone, the liquid silicone has a viscosity of 1800 mPa·S / 25 DEG C-6100 mPa·S / 25 DEG C to adapt to the dipping operation requirements of sponges with different pore diameters, has a curing or operating time of 7-9 h at room temperature to ensure that the liquid silicone in the tank is not solidified before it is used up, has a relatively short curing time of 200 s-400 s at 130 DEG C-160 DEG C to ensure that the liquid silicone attached to the wire diameter of the open sponge can be quickly cured without dropping off from the wire diameter of the open sponge, and has a hardness of 10-20 Shore A after being cured on non-dipping sponges to ensure that the dipping sponge does not cause obvious stinging pain to the patient's wound when it is used.

5. The method of producing a negative pressure wound therapy medical polyurethane sponge according to claim 4, characterized in that, The liquid silicone has a tear strength of 3-7 KN / m and an elongation at break of 500%-900% after curing to ensure that the dipping sponge does not cause the silicone coating on the wire diameter of the open sponge to be broken or dropped due to friction and bending during the negative pressure drainage operation, thereby affecting normal use.

6. The method of manufacturing a negative pressure wound therapy medical polyurethane sponge according to claim 1, wherein, The liquid silicone is obtained by mixing and stirring A component and B component in a certain ratio, wherein the A component comprises base glue, a mixture of two end-vinyl polysiloxanes with different viscosities, and side-chain polysiloxane containing Si-H groups; the B component comprises base glue, a mixture of two end-vinyl polysiloxanes with different viscosities, side-chain polysiloxane containing Si-H groups, a catalyst, and an inhibitor.

7. The method of producing a negative pressure wound therapy medical polyurethane sponge according to claim 6, characterized in that, The mixing ratio of the A component and the B component is one of 5:1, 1:1 or 1:5; the A component and the B component have consistent viscosity.

8. The method of manufacturing a negative pressure wound therapy medical polyurethane sponge according to claim 6, characterized in that, The viscosity of the end-vinyl silicone oil is 1000 mPa·S / 25℃-8000 mPa·S / 25℃, the Si-H group content of the side-chain polysiloxane containing Si-H groups is 5 mmol / g-16 mmol / g, and the base glue is a commercially available product.

9. The method of manufacturing a negative pressure wound therapy medical polyurethane sponge according to any one of claims 6-8, characterized in that, The catalyst is one or more of the eighth group metal, inorganic compound or organic complex; and the inhibitor is an alkyne alcohol.

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